xviii NOTATIONS /', D/ derivative (as a function): 8.1 /'(a), D+/(a) derivative on the right: 8.4 /;03), D_/(j8) derivative on the left : 8.4 integral: 8.7 , exp(x), log x (x real) : 8.8 i/(0i, #2)5 D2/(tfi, a2) partial derivatives: 8.9 derivatives: 8.10 =« /"(*0), D2/(*0),/(»(*0), D*/(x0) higher derivatives: 8.12 /* p regularization: 8.12, prob. 2 <^P)(A) space ofp times continuously differentiate mappings : 8.13. |a|, Ma, Da, DMa (a composite index): 8.13 ez, exp(z) (z complex): 9.5 sin z, cos z sine and cosine: 9.5 7i 9.5 logz, am(z), I I, (1 + zf (z, t complex numbers): 9.5, prob. 8 7° opposite path: 9.6 yl v y2 juxtaposition of paths: 9.6 /(z) dz integral along a road: 9.6 j(a; y) index with respect to a circuit: 9.8 E(z,p) primary factor: 9.12, prob. 1 .T(z) gamma function: 9.12, prob. 2 y Euler's constant: 9.12, prob. 2 /(z) dz integral along an endless road: 9.12, prob. 3 o)(a;/), co(a) order of a function at a point: 9.15 JS?(E) algebra of operators : 1 1 . 1 uv composed operator: 11.1 sp(w) spectrum: 11.1 E(Q, E(C ; u) eigenspace : 1 1 . 1 u continuous extension: 11.2 N(A), N(A; w), F(/l), F(A; w) subspaces attached to an eigenvalue of a com- pact operator: 11.4 k(X), k(l; u) order of an eigenvalue: 11.4 u* adjoint operator : 1 1 .5 I I space of absolutely convergent series: 5.7, prob. 1